This invention relates to a spin wheel calculator for pattern and threshold speeds for a particular aircraft and, more particularly, the invention is concerned with providing an in-flight calculator which will permit the pilot, copilot and/or crewmembers to quickly and safely determine the proper pattern, approach and threshold speeds for a particular aircraft, such as the KC-135, by setting the calculator for the appropriate gross weight and flap setting and taking the proper reading through the speed window.
Heretofore, it has been common practice to provide the pilot of each particular aircraft with all of the critical data required for determining the approach, pattern and threshold speeds of his aircraft. This data is usually in the form of booklets and tables available for each aircraft which are normally incorporated in the operational manual of the aircraft. In order to work out the critical landing information, the pilot is generally required to utilize the operational manual along with one or more computers. It is easy to see that there would be many chances for human error where the pilot must refer to various curves and tables in order to coordinate the information.
It can be seen that it would be most desirable to provide a single instrument with which the pilot would be able to coordinate all of the necessary information without reference to any additional charts and/or tables. During the landing of the aircraft, the time involved in obtaining and coordinating information is critical and the necessary data should be instantaneously available to the pilot in command. Also, the information should be readily available from a source which can be easily carried by the pilot.
The hereinafter described pattern and threshold speed calculator will provide all of the desired features noted above. The speed and accuracy with which the pilot is able to make the various determinations using the subject calculator, will add greatly to the safety of the operation of the aircraft as well as to the safety of all air traffic in the vicinity because the pilot can give his undivided attention to conditions around the airport after the proper pattern and threshold speeds have been quickly calculated. Also, the subject calculator provides the pilot with landing information which the pilot needs based upon the weight of any particular aircraft and permits the determination of the proper approach, pattern and threshold speeds for the aircraft.